The invention relates to hydraulic systems for marine propulsion devices, and, more particularly, to means for supplying hydraulic fluid from a source of fluid inside a boat to hydraulic cylinder/piston assemblies located externally of the boat.
In marine propulsion devices, it is common to have hydraulic cylinder/piston assemblies located externally of the boat for effecting pivotal movement of the propulsion unit relative to its mounting bracket. For example, in marine propulsion devices of the stern drive or inboard/outboard type, it is common to have hydraulic cylinder/piston assemblies connected between the gimbal ring and the propulsion unit for effecting tilting movement of the propulsion unit relative to the gimbal ring. In other types of marine propulsion devices, such as outboard motors, it is known to have hydraulic cylinder/piston assemblies connected between the mounting bracket and the propulsion unit for effecting steering and/or tilting movement of the propulsion unit relative to the mounting bracket.
In many of these marine propulsion devices having hydraulic assemblies located externally of the boat, means are provided for supplying hydraulic fluid to the hydraulic assemblies from a source of fluid inside the boat. Such means typically include hydraulic lines extending from inside the boat to the hydraulic assemblies. This presents several problems.
On problem is whether to run the hydraulic lines over the transom or through the transom and, if through the transom, how to seal the opening through which the hydraulic lines pass.
Another problem, present in marine propulsion devices having two cooperating hydraulic assemblies, is how to supply hydraulic fluid simultaneously to the two assemblies.
Another problem is how to protect the portions of the hydraulic lines extending externally of the transom.
One means for supplying hydraulic fluid simultaneously to a pair of hydraulic assemblies is disclosed in U.S. Hale Pat. No. 4,052,952, issued Oct. 11, 1977. Hale discloses a hydraulic manifold positioned between a pair of tilt/trim cylinders for supplying hydraulic fluid simultaneously to the cylinders. The manifold pivots with the cylinders relative to the mounting bracket and is not fixed to the transom or to the mounting bracket.
Various means have been devised for routing hydraulic lines over or through a boat transom. Some of these means are disclosed in the patents cited below.
Attention is directed to the following U.S. patents which disclose hydraulic systems for marine propulsion devices:
______________________________________ Kern 4,325,700 May 20, 1982 Mayer 3,999,502 December 28, 1976 Ferguson 4,449,945 May 22, 1984 Braun 3,577,953 May 11, 1971 Buddrus 3,915,111 October 28, 1975 ______________________________________
Attention is also directed to U.S. Beavers Pat. No. 3,570,534, issued Mar. 16, 1971, which discloses a hydraulic manifold.